Philadelphia team claims substitute for activated carbon
Researchers at Philadelphia's Temple University claim to have developed a novel adsorbent that is more effective, reusable and environmentally friendly at removing contaminants of emerging concern from wastewater.So far, they have tested the new material against contaminants such as steroid hormones, detergent compounds and bisphenol A in both laboratory water and discharged wastewater and found that it has removed more than 90% of the contaminants.
Professor Rominder Suri, director of the Water & Environmental Technology (WET) center at the university, and his team used cyclodextrins, a family of compounds made up of bound glucose (sugar) molecules, to develop their adsorbent material, which could have a positive impact on the water treatment, pharmaceutical, chemical and manufacturing industries.
Suri said that cyclodextrins have an affinity for attracting organic compounds that is much higher than activated carbon, currently the most common material for removing wastewater contaminants.
"Activated carbon is very porous and water -- whether it be surface water, groundwater or wastewater -- contains a lot of natural organic matter," said Suri. "These are big molecules, and when they hit the activated carbon, they block the pores, which prevents the contaminant particles from getting inside."
Suri said the new adsorbent has a cavity-like area to trap the contaminants, which are made up of organic compounds. By changing the functional groups on the glucose molecule, the size of the cavity can be increased or reduced.
"That means is we can potentially manipulate this adsorbent substance to target and remove select contaminants, something that activated carbon cannot do," he said.
"This new adsorbent material has much less surface area than activated carbon, especially if you coat it on sand," he said. "But our results demonstrate that it has comparable, or even better, capacity than the activated carbon. And, it has the potential to be even more efficient by coating it on porous, high surface materials."